IConnection#onWillSaveTextDocumentWaitUntil is never called

[rictic]

I'm implementing a "fix lint errors on save" feature in my language server. The simplest way to do this seems to be listening for IConnection#onWillSaveTextDocumentWaitUntil and responding with some TextEdits, but my handler is never called. Same thing for IConnection#onWillSaveTextDocument and TextDocuments#onWillSaveWaitUntil.

The IConnection#onDidSaveTextDocument handler is called, and the rest of my language server is working fine (autocomplete, diagnostics, code actions, etc etc).

I'm guessing that there's probably somewhere that I need to opt into receiving these events, but I've been poking around all morning and haven't found anything.

More details:

• my textDocumentSync capability is TextDocuments#syncKind which I think is Full
• transport layer is stdio
• VSCode 1.18.1, vscode-languageserver@3.5.0, vscode-languageclient@3.5.0, vscode-jsonrpc@3.5.0, vscode-languageserver-protocol@3.5.0

[rcjsuen]

@rictic You need to set your capability as a TextDocumentSyncOptions object instead. Please refer to the protocol for more information.

return {
  capabilities: {
    textDocumentSync: {
      willSaveWaitUntil: true,
      change: TextDocumentSyncKind.Full
      /* others you may be interested in... */
    }
  }
}

[rictic]

Perfect! I totally missed that. Thank you!

I sent over a PR adding some docs to that effect to help the next person in my shoes :)

[dbaeumer]

@rcjsuen thanks for explaining this.